JP5812637B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint that can connect a resin pipe such as a cross-linked polyethylene pipe or a polybutene pipe to a pipe for water supply or hot water supply for housing maintenance, for example.

In recent years, the pipes for water supply and hot water supply in residential facilities are mainly used for resin pipes as described above, and many one-touch type pipe joints that can be connected easily and reliably are used as joints for resin pipe joints. Has been.
In this type of pipe joint, sealing with the resin pipe is usually performed by an O-ring or a seal ring, and prevention of the resin pipe from coming off is often performed by a lock ring. In this case, a guide member called an insertion guide may be used to smoothly insert the resin tube and guide the resin tube to a predetermined connection position. When the insertion guide is used, the end face processing at the time of cutting the pipe can be omitted, and the workability is improved because it can be cut with a pipe cutter or the like and directly connected to the joint.

  As this type of pipe joint, for example, a plug-in pipe joint of Patent Document 1 is known. In this pipe joint, an insertion guide having a taper extending forward is fitted in the inner diameter portion. With this pipe joint, when the tube is inserted from the inlet side, it can be inserted and removed until the tip reaches the lock ring tip, and the tube is pushed further so that the tip passes over the lock ring and hits the rear end of the insertion guide. In this case, the inner peripheral tapered surface of the insertion guide presses the O-ring, and the tube passes through the lock ring, so that it cannot be removed by hand.

Japanese Patent No. 4268811

  The plug-in type pipe joint of Patent Document 1 has the following problems. That is, since the inner diameter portion of the insertion guide is a simple tapered surface in this pipe joint, if the portion with the smallest inner diameter of the tapered portion and the inlet side O-ring are arranged opposite to each other to increase the compression allowance of the O-ring, The repulsive force during O-ring compression will be excessive. In this case, when the pipe is inserted, the insertion guide may be pushed away from the pipe end by the repulsive force of the O-ring at a position where the end face does not completely pass through the O-ring. is there. If the tip of the lock ring is in the vicinity of the O-ring at that time, the tube can be inserted / removed in a state where the lock ring is not sufficiently caught in the pipe. The ring may bite and cause water leakage.

Further, for this reason, in the case of a tapered pipe joint having a uniform insertion guide inner diameter as in the literature 1, the distance between the inlet-side O-ring and the lock ring is sufficiently widened. There is a need. For this reason, there exists a tendency for the full length of a joint to become long, and the whole was enlarged.
In addition, when the position where the lock ring presses the pipe is separated from the O-ring, the repulsive force of the O-ring causes the pipe to creep and swell, reducing the pressing force of the O-ring and reducing the sealing force. It cannot be prevented.

  The present invention has been developed in order to solve the above-described problems. The object of the present invention is to achieve smooth operation without biting the O-ring into the end surface of the resin tube even when the resin tube is reinserted. An object of the present invention is to provide a pipe joint that can be connected to the pipe and prevent the resin pipe from undergoing creep deformation while suppressing the decrease in the sealing force while shortening the overall length of the joint.

In order to achieve the above object, in the invention according to claim 1, a resin tube inserted while being guided by an annular insertion guide is connected to a gap between an inner cylinder and an outer cylinder provided in a joint main body with a lock ring so as not to be pulled out. And a pipe joint that is hermetically connected by an O-ring attached to the outer peripheral surface of the inner cylinder, wherein the insertion guide forms an introduction radius portion for guiding the O-ring to the O-ring insertion side, and the introduction radius portion Subsequently, a pressure contact portion for O-ring pressure contact is formed, and a locking end portion for locking the O-ring is provided at a rear end position following the pressure contact portion, and when the resin tube is in a non-connected state, the insertion guide The lock part of the lock ring is temporarily attached to the middle of the outer peripheral part, and the lock part is inserted in the middle of the outer peripheral part of the insertion guide during the insertion from the non-connected state of the resin pipe to the initial insertion state of the resin pipe. Insertion guide from temporary fixing position In the rear end position of the outer peripheral portion of, and by, located between the insertion distance to lock just before the insertion end of the resin pipe, a pipe joint which enables re-insertion of the resin pipe.

The invention according to claim 2 is a pipe joint provided with a smooth rounded surface to the engaging end.

The invention according to claim 3 is a pipe joint formed so that the inner diameter of the locking end portion substantially coincides with the inner diameter of the resin pipe.

The invention according to claim 4 is a pipe joint in which the intersection angle between the tangent to the rounded surface at the locking end and the pipe axis is 30 ° to 45 °.

The invention according to claim 5 is a pipe joint in which the inner diameter of the press contact portion is set to be approximately half of the compression allowance of the inner diameter of the resin pipe compressing the O-ring.

According to the first aspect of the present invention, when the resin pipe is connected, the insertion guide is prevented from getting over the O-ring as long as the resin pipe can be inserted and removed by hand. Since the insertion guide is brought into contact with the end face of the resin pipe without causing a gap between the guide and the end face of the resin pipe, the O-ring is allowed to pass therethrough. The resin pipe can be connected smoothly without biting the O-ring on the pipe end face side. As a result, even when the end surface of the resin pipe is obliquely cut or sharply angled, the insertion guide can smoothly guide the resin pipe end surface over the O-ring while preventing the O-ring from being damaged. This resin tube can be firmly connected while exhibiting sealing properties. Since the lock portion of the lock ring is disposed at the rear position on the tube insertion side of the O-ring, the distance between the lock ring and the O-ring is reduced, and the overall length of the joint can be shortened. Further, from the positional relationship between the lock and the O-ring, the lock ring prevents the resin tube from creeping and expanding due to the repulsive force of the O-ring from the outer surface, thereby suppressing a decrease in the sealing force.

In addition , since the distance between the lock ring and the entrance O-ring can be set short, the overall length of the joint can be further shortened, which can improve productivity and contribute to improvement of workability in a narrow place.

According to the invention of claim 2 , the insertion guide can get over the O-ring by a light insertion force, and the resin tube can be smoothly inserted while preventing the O-ring from being damaged. When the resin tube reaches the lock portion of the lock ring and cannot be pulled out, the insertion guide is moved forward by the repulsive force of the O-ring by embedding the O-ring in the locking end that is a gentle rounded surface. To avoid being pushed out.

According to the invention of claim 3 , it is possible to prevent the end face of the resin tube from projecting from the locking end portion to the enlarged diameter side and prevent the O-ring from being bitten or damaged by the end face of the resin pipe.

According to the invention according to claim 4 , the crossing angle between the tangent line of the rounded surface and the tube axis can be optimized, and it is possible to reliably prevent the insertion guide O-ring from getting over in a state where the resin tube can be inserted and removed. Since the insertion guide can be brought into close contact with the O-ring via the rounded surface when the resin pipe is connected, even an obliquely cut resin pipe can be smoothly guided and connected without damaging the O-ring while ensuring sealing properties.

According to the invention of claim 5 , by setting the compression allowance of the O-ring by the press-contact portion small, the O-ring is prevented from being pressed more than necessary by the press-contact portion, and the O-ring is not dropped or displaced. The resin pipe can be securely connected to the inner part of the joint. In addition, since the O-ring is uniformly compressed by the pressure contact portion, the insertion guide center is aligned with the inner cylinder axis of the joint, and the resin tube can be connected while preventing the insertion in the eccentric state and ensuring the sealing performance.

1 is a half-sectional view showing a preferred embodiment of a pipe joint according to the present invention. It is a principal part expanded sectional view of FIG. It is a principal part expanded sectional view which shows the state which inserted the resin pipe | tube from the state of FIG. It is a principal part expanded sectional view which shows the state which inserted the resin pipe | tube further from the state of FIG. It is a principal part expanded sectional view which shows the state which inserted the resin pipe | tube further from the state of FIG. It is the principal part expanded sectional view which showed the state after the connection of the resin pipe.

  Hereinafter, embodiments of a pipe joint according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a half-sectional view showing a preferred embodiment of the pipe joint according to the present invention, and FIG. 2 is an enlarged cross-sectional view of the main part of FIG.

  In the figure, a pipe joint main body 1 according to the present invention can be connected, for example, with a resin pipe 2 for water supply / hot water supply being prevented from coming off, a joint main body 5 provided with an inner cylinder 3 and an outer cylinder 4, and a cap. 6, a lock ring 7, and an O-ring 8, and an insertion guide 10 is mounted in the pipe joint body 1. As the resin pipe 2, for example, a pipe such as a crosslinked polyethylene pipe or a polybutene pipe can be used. In addition, various resin pipes such as a metal reinforced polyethylene pipe, or a metal pipe such as a copper pipe. Can also be connected.

  The inner cylinder 3 is integrally formed in the joint body 5 in the present embodiment, the outer cylinder 4 is attached to the joint body 5, and a gap G is formed between the inner cylinder 3 and the outer cylinder 4, The resin pipe 2 is inserted into the gap G. The joint body 5 is formed in a cylindrical shape from a highly rigid resin such as a metal such as a copper alloy or PPS (polyphenylene sulfide resin), and has a flow passage port 11 for water passage. The inner cylinder 3 is provided on the side of the joint body 5 to which the resin tube 2 is connected and has an appropriate outer diameter corresponding to the inner diameter of the resin tube 2. The inner cylinder 3 may be attached to the joint body as a separate part.

  A mounting groove 12 is formed in the outer peripheral surface 3 a of the inner cylinder 3, and a rubber O-ring 8 such as EPDM is mounted in the mounting groove 12. With this structure, the pipe joint main body 1 is a one-touch joint having an inner peripheral seal structure in which the inner periphery of the resin pipe 2 is sealed and sealed with an O-ring 8 attached to the outer peripheral surface 3 a of the inner cylinder 3. The mounting grooves 12 are formed at two locations, that is, an inlet side from which the resin pipe 2 of the joint body 5 is pulled out, and an insertion side of the resin pipe 2 from the inlet side. , 8 are mounted.

  An uneven engaging portion 14 is formed on the outer periphery of the joint body 5, and the outer cylinder 4 is attached to the engaging portion 14. A male screw portion 16 is provided on the other side of the joint body 5 with respect to the inner cylinder 3, and a header, a connecting member, or other external piping (not shown) can be connected to the male screw portion 16. The joint body 5 may have, for example, a cheese shape or an elbow shape other than the linear shape as illustrated.

  The outer cylinder 4 is provided with a resin such as amorphous nylon or PPSU (polyphenylsulfone resin) in a transparent or translucent manner, and the resin tube 2 and the insertion guide 10 are inserted from the outside of the outer cylinder 4. Can be seen through.

  A concave storage portion 20 for generating sound and vibration by being struck by the elastic force of an elastic tongue piece 35 to be described later is formed at the inner diameter back portion of the outer cylinder 4. It is formed with a predetermined length in the pipe joint axial direction. This length is formed so that when the insertion guide 10 reaches the depth of the joint, it comes to the primary side from the position where the locking convex portion 38 of the elastic tongue 35 is located, and as shown in FIG. In addition, a distance (space) L that allows the resin tube 2 to be obliquely cut is formed between the position of the locking convex portion 38 and the entrance 20a of the concave storage portion. The distance L is set to a length that can allow a deviation amount of the resin tube described later. On the entrance 20a side of the concave storage portion, a bowl-shaped inner diameter convex portion 21 having a smaller diameter than the inner diameter of the inner peripheral surface 4a of the outer cylinder 4 is formed in an annular shape. The inner diameter convex portion 21 is formed on the joint back side with respect to the position of the end surface 2a of the resin pipe when the insertion is completed when the resin pipe 2 is inserted into the pipe joint main body 1.

  An engagement portion 22 that can be snap-fitted with the engagement portion 14 of the joint body 5 is provided at the attachment position to the joint body 5 on the inner circumference side of the outer cylinder 4, and on the outer circumference side on the other end side. Is provided with an uneven engaging step 23. The outer cylinder 4 is integrated with the joint main body 5 by snap fitting of the engaging portions 14 and 22, and the outer cylinder 4 and the joint main body 5 are rotatable relative to each other after the fitting. Although not illustrated, the inner diameter of the outer cylinder 4 is substantially the same as the dimension of the outer diameter of the resin tube 2 and is provided with a size that allows the resin tube 2 to be inserted without difficulty. An inwardly tapered surface 25 and an R surface 26 that gently connects to the tapered surface 25 are formed on the inner periphery of the outer cylinder 4 on the inlet side.

  The cap 6 is made of, for example, a resin such as polyacetal whose tensile elastic modulus is higher than that of the outer cylinder 4. On the inner peripheral side of the cap 6, an engagement step portion 27 that can be snap-fitted to the engagement step portion 23 of the outer cylinder 4 is formed. The cap 6 is attached to the opening side of the outer cylinder 4 by snap fitting of the engaging step portions 23 and 27, and after the attachment, the cap 6 and the outer cylinder 4 can rotate relative to each other. An annular protrusion 28 protruding in the inner circumferential direction is formed on the end side of the cap 6, and the lock ring 7 is prevented from coming out by the annular protrusion 28 after the outer cylinder 4 is mounted. The cap 6 can also be formed of a material having transparency.

  The lock ring 7 is formed in a substantially annular shape from stainless steel or the like, and includes an annular portion 30 and a lock portion 31 that is a claw portion on the inner diameter side of the annular portion 30. The lock portion 31 is bent from the annular portion 30 at a predetermined inclination angle and can be locked to the surface of the resin tube 2. The lock ring 7 is mounted in a gap 32 formed between the opening side of the outer cylinder 4 and the inner peripheral portion of the cap 6, and the lock portion 31 can be inserted while the resin tube 2 is smoothly inserted by the lock portion 31. When the resin tube 2 is locked and a pulling load is applied to the resin tube 2, the resin tube 2 can be quickly connected in a pull-out preventing state by exerting a pull-in preventing force.

  When locked by the lock ring 7, the resin tube 2 can be hermetically connected by the O-ring 8. At that time, the lock ring 7 is disposed in the pipe joint main body 1 at a position where the lock portion 31 is opposed to the rear position on the pipe insertion side. The rear position on the tube insertion side is the position near the end face of the mounting groove 12 of the inlet side O-ring 8, more specifically, the position from the rear end of the O-ring 8 to the vicinity of the end face of the mounting groove 12.

  The insertion guide 10 shown in FIG. 2 is provided to insert the resin pipe 2 into the pipe joint body 1 while guiding it, and is attached to the gap G between the inner cylinder 3 and the outer cylinder 4. The insertion guide 10 is provided in an annular shape by, for example, a hard resin such as elastic polyacetal, or a soft resin such as polyethylene or polypropylene, and has an introduction radius portion 41, a pressure contact portion 42, an engagement portion on its inner periphery. A toe portion 43 is formed, and a plurality of elastic tongue pieces 35 and a tapered surface portion 36 are formed on the outer periphery.

  The introduction radius portion 41 is formed on the O-ring insertion side of the insertion guide 10 by an arc portion, and the O-ring 8 can be guided to the introduction radius portion 41. The pressure contact portion 42 is formed on the inner peripheral surface 10 a of the insertion guide 10 following the introduction radius portion 41, and the inner diameter D of the pressure contact portion 42 is an intermediate dimension between the outer diameter of the O-ring 8 and the inner diameter of the resin tube 2. It has become. More specifically, the inner diameter D of the press contact portion 42 is larger than the inner diameter of the resin tube 2, and the compression allowance (crushing allowance) when the press contact portion 42 compresses the O-ring 8 is the inner diameter of the resin tube 2. It is set to be approximately half smaller than the compression allowance when the O-ring 8 is compressed. Further, by making the inner diameter of the press contact portion 42 larger than the inner diameter of the locking end portion 43, the compression allowance of the O-ring 8 by the press contact portion 42 is smaller than the compression allowance by the engaging end portion 43. Is set. As a result, the O-ring 8 does not receive a large load from the press contact portion 42, and the insertion guide 10 and the resin tube 2 can be smoothly inserted into the gap G.

  The locking end portion 43 is provided for locking the O-ring 8 at the rear end position following the press contact portion 42, and the inner diameter of the locking end portion 43 is formed so as to substantially match the inner diameter of the resin tube 2. ing. In FIG. 2, the locking end portion 43 is connected to the pressure contact portion 42 via a gentle rounded surface 44.

  The rounded surface 44 may be of any appropriate size, but as shown in FIG. 2, the crossing angle α between the tangent S of the rounded surface 44 at the locking end 43 and the tube axis P of the joint body 5 is 30˜. It is preferable to provide it at about 45 °. Further, a tapered surface (not shown) may be provided between the pressure contact portion 42 and the locking end portion 43 instead of the rounded surface 44. The locking end portion 43 is formed in an annular flange shape on the contact surface side of the resin tube 2 in order to ensure ease of molding and strength of the rounded surface 44.

In this way, the contact portion of the insertion guide 10 with the O-ring 8 is the introduction radius portion 41 that first contacts the O-ring 8, the pressure-contact portion 42 that presses the O-ring 8, and the pressure-contact portion 42 that is stronger than the pressure-contact portion 42. The ring 8 can be press-contacted, and is constituted by a three-stage surface including a locking end portion 43 having a rounded surface 44.
In the case of forming each portion of the introduction round portion 41, the pressure contact portion 42, and the locking end portion 43, for example, if the compression allowance of the O-ring 8 is designed to be about 15% or less in the pressure contact portion 42. Good. This compression allowance can be set to an appropriate size and can be larger than a little less than 15%. In addition, you may form the introduction round part 41 in a taper shape.

  By the way, in general, when connecting a resin pipe without using an insertion guide, the resin pipe can be inserted without damaging the O-ring in accordance with a standard for designing an O-ring (O-ring). For example, it is necessary to provide a chamfer defined by JIS B 2401 or the like on the inner periphery of the tip of the resin tube. For this reason, it is desirable to insert the resin tube after chamfering the inner periphery of the tip after cutting the resin tube. However, in practice, it is necessary to improve the work efficiency of the piping work site. Therefore, it is difficult to apply a smooth chamfering that satisfies this standard, and if new beveling occurs in this chamfering process, the beveling is sandwiched between the sealing surfaces of the O-ring and sealed. It may become a factor to inhibit. For this reason, at work sites, in order to avoid the occurrence of whiskering and the like, the resin tube is often used for connection without being chamfered after being cut with a dedicated cutter or the like.

  Therefore, the pipe joint main body of the present invention is provided with the insertion guide 10 by the above-described three-stage configuration, and the O-ring 8 exhibits a predetermined compression allowance for the outer diameter dimension of the mounting groove 12 for mounting the O-ring 8. By providing it in such a size, the resin tube 2 can be easily inserted while ensuring high sealing performance by the O-ring 8. Thus, when the resin tube 2 is inserted, the resin tube 2 is guided smoothly while the O-ring 8 is pressed in the inner diameter direction by the insertion guide 10 into the gap G between the inner tube 3 and the outer tube 4. It becomes possible to connect to.

  On the other hand, on the outer periphery of the insertion guide 10, the elastic tongue pieces 35 are formed at equal intervals at a plurality of locations, for example, at four locations on the insertion guide 10. The elastic tongue 35 is larger than the inner diameter of the outer cylinder 4 so as to protrude outwardly from the outer peripheral portion of the insertion guide 10 so as to be bowed, and is further provided with a concave accommodating portion 20 provided in the inner part of the outer cylinder 4. The dimensions are set so that the outer diameter is the same as or slightly larger than the inner diameter.

A locking projection 38 is formed at the end of the elastic tongue piece 35, and this locking projection 38 can be locked to the inner diameter projection 21 provided at the starting end position of the concave storage portion 20 shown in the figure. ing. When the insertion guide 10 is pushed by the resin tube 2 and moves in the back direction in the gap G and the locking projection 38 is locked to the inner diameter projection 21, elastic energy is stored in the elastic tongue piece 35. . The elastic tongue piece 35 is provided in a size that can be stored in the concave storage portion 20.
The tapered surface portion 36 is formed on the outer periphery near the rear end of the insertion guide 10 so as to be inclined at a predetermined angle from the insertion direction of the insertion guide 10.

  In the insertion guide 10, a mounting recess 40 is formed on the outer periphery thereof by an elastic tongue piece 35, a tapered surface portion 36, and an outer peripheral portion 37 positioned therebetween. The insertion guide 10 is temporarily attached between the lock ring 7 and the O-ring 8 so that the lock portion 31 of the lock ring 7 is fitted into the attachment recess 40, and the temporary attachment prevents the drop-out from the pipe joint body 1. It is prevented. In a non-connected state of the resin pipe 2, the insertion guide 10 is positioned at the lock portion 31 in a state of being opposed to the position near the end face of the entrance-side O-ring mounting groove 12.

When the resin tube 2 is in the initial insertion state, the insertion guide 10 is inserted by this resin tube, and the rear end side of the press contact portion 42 is pressed by the O ring 8 or the O ring is moved to a position near the locking end portion. The lock ring 7 is positioned in a state immediately before locking on the insertion end side of the resin tube 2 in a state in which 8 is pressed.
When the insertion of the resin pipe 2 is completed, the pipe joint main body 1 generates sound and vibration by the elastic tongue piece 35 having an enlarged diameter colliding with the concave storage portion 20 of the outer cylinder 4 by its elastic force. ing.

Subsequently, an operation when the resin pipe 2 is inserted and connected to the pipe joint body 1 configured as described above will be described.
1 and 2 show a state of starting insertion of the resin tube 2 when the resin tube 2 is inserted, and the end surface 2a comes into contact with the insertion guide 10 attached to the pipe joint body 1 in a temporarily fixed state. Showing the moment. In the non-connected state before the insertion guide 10 is inserted, the insertion guide 10 is positioned in a state where the lock portion 31 of the lock ring 7 is opposed to the rear position before the tube insertion of the O-ring 8 as described above. .

  When the resin pipe 2 is inserted into the pipe joint body 1 up to the state of FIG. 3, the insertion guide 10 is inserted and the rear end side of the pressure contact portion 42 is pressed against the O-ring 8 or a position near the locking end portion 43. Until the O-ring 8 is in pressure contact. At this time, the inlet-side O-ring 8 is compressed by the press-contact portion 42 of the insertion guide 10 to be slightly looser than a predetermined compression allowance. The insertion guide 10 is supported by the outer diameter of the O-ring 8 and is automatically aligned with respect to the axial center of the pipe joint so that the misalignment with the resin pipe end surface 2a is prevented.

  In such an initial insertion state of the resin tube 2, the lock ring 7 is positioned immediately before locking on the insertion end side of the resin tube 2. The resin pipe end surface 2a is in contact with the lock portion 31. In this state, the resin pipe 2 can be extracted from the pipe joint body 1. Even when the resin tube is pulled out and inserted again, the insertion guide 10 does not pass through the O-ring 8 on the entrance side, so the insertion guide 10 and the end surface 2a are inserted in close contact with each other, and the end surface 2a is inserted. There is no risk of biting the O-ring 8.

  When the resin tube 2 is further inserted, the insertion guide 10 is pushed by the resin tube 2 and begins to move in the depth direction, and as shown in FIG. 43 presses the inlet-side O-ring 8. At this time, because the locking end 43 is locked to the O-ring 8, the insertion guide 10 is in a braked state and its movement is restricted. When the insertion of the resin tube 2 is continued in this state, the insertion guide 10 is pressed by the resin tube end surface 2a, and the gap between the insertion guide 10 and the resin tube 2 becomes extremely small.

  In this state, since the lock portion 31 bites into the resin tube 2, it becomes difficult to pull out the resin tube 2 by hand. Since the insertion guide 10 includes the O-ring 8 due to the shape of the rounded surface 44, the insertion guide 10 is prevented from being pushed out to the joint back side by the repulsive force of the O-ring 8. As a result, even if the resin tube 2 is shaken and pulled out and reinserted, the insertion guide 10 is at the position of the entrance side O-ring 8, so that the end surface 2 a that has passed the position of the lock portion 31 becomes the entrance side O-ring 8. Before coming into contact, it comes into contact with the insertion guide 10, and the resin pipe end surface 2 a is prevented from biting the O-ring 8.

  When the insertion force exceeds the engagement force between the locking end portion 43 and the entrance-side O-ring 8, the insertion guide 10 moves over the O-ring 8 without moving away from the resin pipe end surface 2a. Also at this time, the end face 2a is prevented from coming into contact with the O-ring 8 and damaging or biting the O-ring 8. Further, while preventing the phenomenon of causing the O-ring 8 to jump out of the mounting groove 12. The resin tube 2 can be inserted. Moreover, the pressure contact portion 42 which is a diameter between the outer diameter of the O-ring 8 and the inner diameter of the resin tube 2 and which is about half the compression allowance by the resin tube 2 presses the O-ring 8, and subsequently Since the O-ring 8 is pressed by the rounded surface 44 and the locking end portion 43 that continue from the pressure contact portion 42, the force required to compress the O-ring 8 can be minimized.

  FIG. 5 shows a state where the pipe is further pushed in from the state of FIG. In the figure, the resin tube 2 is in a state of passing through the inlet-side O-ring 8, and at this time, it is impossible to pull out the resin tube by hand.

  When the resin tube 2 is continuously inserted, the introduction round portion 41 of the insertion guide 10 comes into contact with the back O-ring 8 and the insertion ring 10 rides on the back O-ring 8. Since the inner diameter of the pressure contact portion 42 is set to be smaller than the outer diameter of the O-ring 8 and larger than the inner diameter of the resin tube 2 as described above, the insertion guide 10 is smoothly inserted.

In the insertion process of the insertion guide 10, the elastic tongue piece 35 and the locking projection 38 are in contact with the tapered surface 25 of the outer cylinder 4 on the outer peripheral side, and the tapered surface 25 is brought into contact with the insertion of the resin tube 2. Subsequently, these are accommodated in the gap G while being deformed along the formed R surface 26.
On the other hand, the rounded surface 44 is guided by the O-ring 8 on the inner peripheral side of the insertion guide 10, and the insertion guide 10 is in a state where the outer peripheral side and the inner peripheral side are thus supported and the centering action is exhibited. It is inserted at a predetermined position in the gap G. In addition, the O-ring 8 is prevented from being damaged, and the resin pipe 2 is secured to the inside of the pipe joint body 1 while the sealing performance when the resin pipe 2 is inserted is secured by the O-ring 8 on both the back side and the entrance side. Can move to.

  Of the O-rings 8 and 8 mounted at two locations, the inlet-side O-ring 8 is pre-compressed by the pressure contact portion 42 of the insertion guide 10, so there is a merit that the insertion load becomes lighter, There is also an effect that the insertion load due to the lock ring 7 arranged to face each other can be reduced.

  When the resin pipe 2 is further inserted after the locking end portion 43 comes into contact with the O-ring 8 on the back side, the insertion guide 10 is pressed by the end surface 2a and moves to the back side of the pipe joint body 1. At this time, the diameter of the elastic tongue 35 is reduced by the inner peripheral surface 4a of the outer cylinder 4, elastic energy in the radial direction is stored in the elastic tongue 35, and the elastic tongue 35 is strongly pressed against the inner peripheral surface 4a. In this state, the insertion guide 10 moves toward the inside of the pipe joint body 1. Therefore, even if the pipe joint main body 1 is disposed in a direction in which the resin pipe 2 is inserted in the gravity direction, the resin pipe end surface 2a is caused by gravity after the insertion guide 10 gets over the O-ring 8 on the back side. It is prevented that it falls apart and falls to the back side of the pipe joint main body 1.

  As shown in FIG. 6, when the resin tube 2 is further inserted, the insertion of the resin tube is completed. Before the connection is completed, when the locking projection 38 gets over the inner diameter projection 21, the elastic tongue 35 is expanded in diameter by the elastic energy accumulated at that moment, and is reduced in its original state or slightly reduced in diameter. Restore to the original state. At this time, the engaging projection 38 collides with the concave accommodating portion 20 to generate vibration and sound. The operator can confirm that the resin pipe 2 is connected in a state of being securely inserted to a predetermined position by confirming the vibration and sound.

  After the insertion is completed, the locking convex portion 38 is stored in the concave storage portion 20. Further, since a distance L that allows the resin tube 2 to be obliquely cut is provided between the position of the locking convex portion 38 of the elastic tongue 35 and the entrance 20a of the concave storage portion 20, an obliquely cut resin tube (not shown) is provided. , The engaging convex portion 38 can be accommodated in the concave accommodating portion 20 while absorbing the shift in the length direction of the resin pipe end surface by this distance L. For this reason, the resin pipe can be reliably connected to the back side of the pipe joint body 1. Moreover, since the space part when the latching convex part 38 collides with the concave storage part 20 becomes large by this distance L, the collision sound by the latching convex part 38 is reflected by this spatial part, and the collision sound and vibration are generated. Become bigger.

  As described above, in the pipe joint of the present invention, when the resin pipe 2 is not connected, the insertion guide 10 is positioned in a state where the lock portion 31 is disposed opposite to the rear position on the pipe insertion side of the O-ring 8. At the same time, when the resin tube 2 is in the initial insertion state, the insertion guide 10 is inserted and the rear end side of the pressure contact portion 42 is pressed against the O ring 8 or the O ring 8 is moved to a position near the locking end portion 43. The lock ring 7 is in pressure contact with the insertion end of the resin tube 2 and is positioned immediately before locking. Therefore, the insertion guide 10 can be inserted into the O-ring 8 within a range where the resin tube 2 can be inserted and removed by hand. Even when the resin tube 2 is reinserted to prevent getting over, the insertion guide 10 is brought into contact with the resin tube end surface 2a without causing a gap between the insertion guide 10 and the resin tube end surface 2a. Then pass through the O-ring 8. The resin pipe 2 can be connected without biting an O-ring 8 in the pipe end face 2a Te. For this reason, the sealing performance by the O-ring 8 can be maintained. Furthermore, since the rear position on the tube insertion side is located near the end face of the mounting groove 12 of the inlet side O-ring 8, the lock ring 7 and the inlet side O-ring 8 can be arranged to face each other, thereby shortening the overall length of the joint. In addition, the creep deformation of the resin tube 2 can be suppressed to ensure high sealing performance.

  Further, the locking end portion 43 is gently connected to the pressure contact portion 42 via the rounded surface 44, and the crossing angle α between the rounded surface 44 and the tube axis P is set to 30 to 45 °, so that the resin pipe is in a diagonally cut state. Even so, the resistance when the locking end 43 gets over the O-ring 8 gradually increases from the rounded surface 44 to the locking end 43. Therefore, it is possible to prevent only the insertion guide 10 from being pushed out in advance and to connect over the O-ring 8 while the insertion guide 10 is in close contact with the resin pipe end surface 2a. Thus, even in the case of oblique cutting, the resin tube 2 can be guided and connected by the insertion guide 10 while preventing the resin tube 2 from biting the O-ring 8.

  The embodiment of the pipe joint according to the present invention has been described in detail above, but the present invention is not limited to the description of the embodiment, and departs from the spirit of the invention described in the claims of the present invention. Various changes can be made without departing from the scope.

  As a result, various types of pipe joints having a structure in which a resin pipe is inserted into the gap between the inner cylinder and the outer cylinder provided in the joint body and the resin pipe is hermetically connected with an O-ring while preventing the resin pipe from being pulled out. For example, an outer cylinder can be integrally formed on the joint body, and the inner cylinder provided separately can be fixed to the joint body by an appropriate fixing means such as fitting. In addition, it is possible to make changes such as increasing the lock ring to enhance the resin tube removal prevention effect. In this case, the positional relationship between the lock ring, the O-ring, and the insertion guide in the present invention may be applied to the lock ring that is disposed closest to the entrance side.

DESCRIPTION OF SYMBOLS 1 Pipe joint main body 2 Resin pipe 3 Inner cylinder 3a Outer peripheral surface 4 Outer cylinder 5 Joint main body 7 Lock ring 8 O-ring 10 Insertion guide 31 Lock part 41 Introducing round part 42 Press-contact part 43 Locking end part 44 Round face D Inner diameter G Gap S Tangent P Pipe axis α Crossing angle

Claims (5)

An O-ring attached to the outer peripheral surface of the inner cylinder is connected to a resin pipe to be inserted while being guided by an annular insertion guide in a gap between the inner cylinder and the outer cylinder provided in the joint body in a state of preventing pulling with a lock ring. A pipe joint for sealing connection, wherein the insertion guide forms an introduction radius portion for guiding the O-ring on the O-ring insertion side, and subsequently forms a pressure contact portion for O-ring pressure welding following the introduction radius portion, A locking end portion for locking the O-ring is provided at the rear end position following the pressure contact portion, and when the resin tube is not connected, the lock portion of the lock ring is temporarily fixed in the middle of the outer peripheral portion of the insertion guide. The lock portion is mounted from the temporarily fixed position in the middle of the outer periphery of the insertion guide to the rear end position of the outer periphery of the insertion guide during the insertion from the non-connected state of the resin tube to the initial insertion state of the resin tube. And the insertion end side of the resin pipe By located between the insertion distance to lock just before the pipe joint is characterized in that it possible to reinsert the resin tube.   The pipe joint according to claim 1, wherein a smooth rounded surface is provided at the locking end portion.   The pipe joint according to claim 1 or 2, wherein an inner diameter of the locking end portion is formed so as to substantially coincide with an inner diameter of the resin pipe.   The pipe joint according to claim 1 or 2, wherein an angle of intersection between a tangent line of the rounded surface and the pipe axis at the engagement end portion is 30 ° to 45 °.   2. The pipe joint according to claim 1, wherein an inner diameter of the press contact portion is set to be approximately half of a compression allowance for compressing the O-ring.

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